Abstract
Two-dimensional (2D) materials have recently attracted significant interest in condensed-matter physics and materials science due to rich intriguing physics and potential applications. Here, by first-principles calculations, we discover a phase of transition-metal dichalcogenides and its family) named the phase. We demonstrate that monolayer has multiple topological phase transitions from a topologically trivial insulator state to a 2D type-II Dirac semimetal state, and then to a 2D ideal type-I semimetal state under a moderate tensile strain. The Dirac points are protected by the coexistence of space-inversion and time-reversal symmetry. Our results highlight a family of nonhoneycomb 2D Dirac semimetals with potential application in nanoelectronics.
- Received 31 October 2019
DOI:https://doi.org/10.1103/PhysRevB.100.235435
©2019 American Physical Society